Cancer cells secrete many exosomes, which facilitate metastasis and the later growth of cancer. For early cancer diagnosis, the detection of exosomes is a crucial step. Exosomes exist in biological fluid, such as blood, which contains various proteins. It is necessary to remove the proteins in the biological fluid to avoid test interference. This paper presented a novel method for exosome isolation using Fe3O4 magnetic nanoparticles (MNPs), which were synthesized using the chemical co-precipitation method and then coated with polyethylene glycol (PEG). The experimental results showed that the diameter of the PEG-coated Fe3O4 nanoparticles was about 20 nm, while an agglomerate of MNPs reached hundreds of nanometers in size. In the protein removal experiments, fetal bovine serum (FBS) was adopted as the analyte for bioassays of exosome purification. PEG-coated Fe3O4 MNPs reduced the protein concentration in FBS to 39.89% of the original solution. By observing a particle size distribution of 30~200 nm (the size range of various exosomes), the exosome concentrations were kept the same before and after purification. In the gel electrophoresis experiments, the bands of CD63 (~53 kDa) and CD9 (~22 kDa) revealed that exosomes existed in FBS as well as in the purified solution. However, the bands of the serum albumins (~66 kDa) and the various immunoglobulins (around 160 ~ 188 kDa) in the purified solution’s lane explained that most proteins in FBS were removed by PEG-coated Fe3O4 MNPs. When purifying exosomes from serum, protein removal is critical for further exosome investigation. The proposed technique provides a simple and effective method to remove proteins in the serum using the PEG-coated Fe3O4 MNPs.

Monitoring surface species and their bonding structures in link to specific chemical processes has long been an active, important subject in heterogeneous catalysis. In this article, with employment of temperature-programmed reaction/desorption, reflection− absorption infrared spectroscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy in combination with density functional theory computation, we present three CH 3 CN formation channels from reaction of CH 2 CN generated by ICH 2 CN dissociative adsorption on Cu(100) and first spectroscopic evidence for CHCN on single crystal surfaces. The CH 3 CN formation mechanisms are dependent on CH 2 CN adsorption geometries. At lower coverages, CH 2 CN is adsorbed with the C−C−N approximately parallel to the surface. Reaction of these adsorbates produces CH 3 CN via firstand second-order kinetics, with the largest desorption rates occurring at 213 K and ∼400 K, respectively. At or near a saturated first-layer coverage, decomposition of ICH 2 CN forms C-bonded CH 2 CN (−CH 2 CN), which then transforms to N-bonded −NCCH 2 with tilted orientation. Disproportionation of the −NCCH 2 generates CH 3 CN at ∼324 K. Thermal products of H 2 , HCN and (CN) 2 evolving at higher temperatures are originated from the CHCN dissociation. On oxygen-precovered Cu(100), reaction of CH 2 CN forms new surface intermediates of vertical −NCO and −CCO, in addition to perturbed CH 3 CN desorption. In the conditions studied, formation of H 2 , HCN, and (CN) 2 is terminated due to the presence of preadsorbed O. −NCO and −CCO on O/Cu dissociate at ∼525 and 610 K, respectively, into CO and CO 2 .

In this study, one-pot hydrothermal synthesis of sheet-like ZSM-5 as a high-performance catalyst for toluene disproportionation was carried out using binary surfactants. In the dual template, tetraethylammonium hydroxide was used to construct the microporous structure of ZSM-5, and cationic surfactant (e.g., octadecyltrimethylammonium chloride (C 18 TMAC), hexadecyltrimethyl ammonium bromide (C 16 TMAB), and tetradecyltrimethylammonium bromide, (C 14 TMAB)) can change the growth habits of the ZSM-5 crystals by hindering the regular stacking of zeolite layers from their longer hydrophobic chain. From the XRD pattern of the as-synthesized samples which were hydrothermally treated for different time, it was found that a lamellar mesostructured intermediate gradually transformed into the sheet-like ZSM-5 during hydrothermal process. With a proper amount of cationic surfactant, the thickness of the sheet-like ZSM-5 could be controlled to less than 30 nm. Concerning the catalyst application, the toluene disproportionation performance over the sheet-like ZSM-5 is 1.5 times higher than that of the commercial ZSM-5. The higher conversion is ascribed to the faster diffusion amount due to the sheet-like ZSM-5.

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This article studies the reactions and mechanisms of H 8 Si 8 O 12 (T 8 H 8 ) molecules with n-propanol, acetone, allyl alcohol, n-butylamine, allylamine, acetic acid, and 1-octene in air, at room temperature, and without catalysts. The reaction between T 8 H 8 and n-propanol involves both the highly polarized Si O and Si H bonds and results in cage breakage and forming Q 4 and Q 3 structures with OC 3 H 7 in the reaction product. T 8 H 8 also reacts with acetone, and the resultant product possesses Si OCH(CH 3 ) 2 . Allyl alcohol is less reactive to cause T 8 H 8 decomposition, and the resultant product contains Si OCH 2 CH CH 2 and Si OCH 2 (CH 2 ) 3 CH CH 2 . However, it is found that basically T 8 H 8 does not react with acetic acid and 1-octene. In the reactions of T 8 H 8 with n-butylamine and allylamine, the resultant products contain Si NH(CH 2 ) 3 CH 3 and Si NHCH 2 CH CH 2 , respectively. For the reaction with T 8 H 8 , allylamine is less active than n-butylamine. Possible mechanisms for the T 8 H 8 reactions are discussed. K E Y W O R D Sacetone, allyl alcohol, allylamine, H 8 Si 8 O 12 , n-butylamine, n-propanol, silsesquioxane